We all know how painful ripping off a band-aid can be. It may not be so unpleasant in the not-too-distant future, however, as scientists have created an adhesive that detaches in the presence of ultraviolet light.
Developed in a partnership between Harvard University and China's Xi'an Jiaotong University, the adhesive takes the form of an aqueous solution of polymer chains.
This solution gets sandwiched between two materials that the user wishes to temporarily join together, essentially stitching their facing surfaces to one another at a molecular level – the process is known as topological entanglement. The two materials then stay securely bonded, until the solution is exposed to ultraviolet light. This causes its molecular "sutures" to dissolve, allowing the materials to be easily pulled back apart.
The adhesive works both on solid materials such as elastomers, as well as wet materials like hydrogels. To that end, it could be used not only to adhere band-aid strips to the skin, but it could also be used to keep hydrogel-based dressings directly on wounds, without undoing any healing that has taken place once those dressings are removed.
The technology could additionally be utilized on transdermal drug delivery devices (microneedle patches that deliver medication through the skin), or on wearable electronics. All this being said, ultraviolet light is harmful to the skin in large doses. To that end, the scientists are now looking into using skin-safe near-infrared light to trigger the detachment.
A paper on the research was recently published in the journal Advanced Materials.
Source: Harvard John A. Paulson School of Engineering and Applied Sciences via EurekAlert